4 Low humming/whining, 2H and 4H no sounds

[PlayfulBird]

Do your Glads sound different driving after you switch from 4H (no noises) to 4L?
Hum or whine is directly changed by the speed I am going.

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[PlayfulBird]

No one, not even to confirm no noise in 4 low?

Could it just be that the ratio on the Rubicon is so much lower than I am used to from other vehicles and that everything is just humming from moving that much more?

Definitely not the rev from the engine.

 

[BearFootSam]

I can't recall off the top of my head, but in other vehicles I've driven this has been the case. Consider, the transfer case is after the transmission so any gear whine or noise that the transmission would generate during 2Hi/4Hi that would be masked by road/wind noise as speed increased would be audible in 4Lo since the tranny is turning at say the normal 20mph speed when you are only going 5mph.

The planetary gear set will also make some noise potentially, particularly when new. I'd bet that the noise will diminish somewhat as the system breaks in.

If the noise is consistent with vehicle speed, sounds like gear whine and is 'smooth' (not 'gritty') I wouldn't worry about it. If it sounds 'off' take it into the dealer and let them confirm or at least get it on the record.

Compared to many other modern vehicles, the jeeps have very little sound deadening and are to a degree crude. Not to say poor quality but the more rudimentary construction that is part of their appeal.

 

[JRobes]

I don't have the Rubicon, but yes it will make a bit more whine/noise when in low gear, more noticeably when you get your speed up. Hopefully you're not going too fast in low gear, especially on the Rubicon model due to its rock crawling (very low speed) optimized t-case.

 

[Arcticelf]

No one, not even to confirm no noise in 4 low?

Could it just be that the ratio on the Rubicon is so much lower than I am used to from other vehicles and that everything is just humming from moving that much more?

Definitely not the rev from the engine.

yeah, you can hear the T-case working in low range. true for most trucks.

 

[PlayfulBird]

yeah, you can hear the T-case working in low range. true for most trucks.

Ty. Used to Defenders and older Hilux and Navara Pickups. Tbh it was always to loud in general to hear anything, never mind tell the difference 4h to 4low in the Defender. The others I never heard anything in.

 

[dcmdon]

Do they use straight cut (rather than helical cut) gears in low?

To the OP. Most transmissions use straight gears for reverse. If the noise is similar then it may because low range uses straight cut gears.

It won't be identical because in reverse you are getting noise from the transmission, in 4 low going forard the noise will be from the transfer case.

Either way, I'll give it a test today, I'll be driving on a fire road this afternoon.

 

[Trailman]

Definitely sounds different. I think it sounds similar to a side by side/razer tbh. I drove with a guy who has a tundra who said "woh it even sounds like a side by side!" when we had it in low.

(Specifically the Rubicon with low case.)

 

[dcmdon]

I'll check my Mojave shortly. It's a different transfer case, but I'd have to think that if they use straight cut gears for low range on one, they'd use it on the other.

 

[PlayfulBird]

Do they use straight cut (rather than helical cut) gears in low?

To the OP. Most transmissions use straight gears for reverse. If the noise is similar then it may because low range uses straight cut gears.

It won't be identical because in reverse you are getting noise from the transmission, in 4 low going forard the noise will be from the transfer case.

Either way, I'll give it a test today, I'll be driving on a fire road this afternoon.

In the Navara we had the Patrol Axle swapped in with these bad boys. Helical but was fun they were solid

no clue what was in the Hilux. Was a beater for the quarry.

 

[PlayfulBird]

Hopefully you're not going too fast in low gear, especially on the Rubicon model due to its rock crawling (very low speed) optimized t-case.

I think the fastest I ever went was 15 mph (was definitely under 25km/h). Wheel spin in the mountains is hard to tell though what it would have been. Motor did rev a bit more than I like, but am used to diesels so...
Just was worried, no wind, just thought it has been a few months let me put it in low and let me press all the buttons to see that nothing seized and everything is working.

 

[PlayfulBird]

that would be masked by road/wind noise as speed increased would be audible in 4Lo since the tranny is turning at say the normal 20mph speed when you are only going 5mph.

The planetary gear set will also make some noise potentially, particularly when new. I'd bet that the noise will diminish somewhat as the system breaks in.

If the noise is consistent with vehicle speed, sounds like gear whine and is 'smooth' (not 'gritty') I wouldn't worry about it. If it sounds 'off' take it into the dealer and let them confirm or at least get it on the record.

Did not sound gritty, but reminded me a bit of a somewhat unbalanced (muddy) cardan (/prop) shaft without all the vibration but the sound of it. Sorry, my translator is not sure what is correct

Dealer I can take it to for sure.
Record, they don't care. I bought an import. Jeeps in the clear and the SkyBison is our problem ?
Kinda loving it. Living dangerous

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